The purpose of this study is to analyze the damage to trusses of the Church of the Annunciation of the Virgin Mary and make a recommendation for their repair. The part of the dissertation is a research technique to assess main frame of the most commonly used historical main frames. The building has been measured and assessed and this will be undertaken by: Making 3D documentation and model including all rafter connections. On the basis of this research it has been produced a repair methodology. Last but not least an estimate of the costs has been also made. The benefit of the dissertation is to preserve trusses to ensure the building function will be kept. Key words